Rakes, having a plurality of finger wheels mounted on a cross beam, for sweeping material into a windrow are well known and by way of example reference maybe had to the following U.S. Pat. No. 4,183,198 Issued Jan. 15, 1980 to H. Sligter, and U.S. Pat. No. 5,313,772 issued May 24, 1994 to C. Tonutt. These rakes have a cross beam supported by a pair of ground engaging wheels and a draw bar that extends forwardly from the cross beam. The draw bar can be hooked up to a tractor and towed thereby.
There are some rakes of the foregoing type that are mounted on the tractor at or proximate the front thereof. The rake maybe fixed to a front end loader mounted on the tractor. Reference maybe had to the following U.S. Pat. No. 4,753,063 issued Jun. 28, 1988 to G. Buck and U.S. Pat. No. 5,966,916 issued Oct. 19, 1999 to M Laing.
It is also known to have the rake located at the front of the vehicle so as to sweep the material on the ground into a windrow that is picked up by a machine, for example a baler, being towed behind the tractor. This combines raking and baling of raked material into a single operation. Reference may be had to the following Canadian Patent 1.066,068 issued Nov. 13, 1979 to W. C. Hering and U.S. Pat. No. 4,214,428 issued Jul. 29, 1980 to R. Caraway and U.S. Pat. No. 5,987,964 issued Nov. 23, 1999 to H. Lutz.
The front mounted rake maybe fixedly secured to the tractor whereby it changes direction simultaneously with any directional changes the tractor may make while moving. The rakes are conventionally supported by caster wheels that are in rolling engagement with the ground and any change in the direction of travel results in the caster wheel assembly pivoting about its pivotal connection to the frame of the rake such pivotal movement being about a generally vertical axis. This is the normal function of a caster wheel. There are however numerous occasions when the wheel assembly becomes unstable and will oscillate back and forth ‘hunting’ or ‘searching’ for a stable position. This movement is most undesirable as it induces vibrations resulting in abnormal wear and tear on the machine as well as on the caster wheel assembly.
Hunting movement of a caster wheel referred to in the forgoing is pronounced in instances where the caster wheels are being pushed as is the case with the rake mounted on the leading end of the tractor and pushed by the same.